The application generally relates to spectral sensors for solar irradiance. The application relates more specifically to a fixed position spectral sensor for solar radiation, atmospheric monitoring, sensing of atmospheric particulates and methods of spectral irradiance analysis for positioning photovoltaic (PV) arrays.
Current photovoltaic (PV) installations require large financial investments. To get an improved positive return on the investment, PV technology must be better matched to the solar spectral resource at a solar power generating location. Improved matching of the solar spectral resource requires extended monitoring of the solar spectrum using a spectrometer. Solar spectrometers may be expensive and difficult to implement in practice. Tracking systems that tilt or reposition the spectral sensors require complex mechanical systems and may introduce error in the data when the positioning systems wear over time.
Site-specific solar spectrum needs to be considered to most effectively utilize the solar resources at a given location. Decisions can then be made on the appropriate solar technology to optimize power generation. The rise of commercially relevant non-silicon thin film PV materials such as copper indium gallium selenide (CIGS) and cadmium telluride (CdTe) provides different bandgaps that can be employed for local spectra that can be red- or blue-shifted from the Standard Tables for Reference Solar Spectral Irradiances published in ASTM G173 standard.
Furthermore, spectral ratios that differ from the norm can influence the overall production in multi-junction PV cells by changing the current limiting junction. Specific, geographically varying atmospheric components like water vapor and dust aerosols can affect the spectrum and must be accounted for when addressing variations in spectral ratios. After a suitable PV technology is selected for a site, the daily solar spectrum must monitored to accurately predict the performance of the PV system Spectrometer systems that are capable of delivering this information are often expensive, require maintenance, delicate, data intensive, and can be challenging to implement in the field. Various spectrometers are available on the market.
What is needed is a system and/or method that satisfies one or more of these needs or provides other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the claims, regardless of whether they accomplish one or more of the aforementioned needs.